Integrated resistor for sensing electrical parameters

Abstract

A leadframe for sensing electrical parameters in an integrated circuit package includes an interconnect pattern having a plurality of patterned conductive pads connected to a plurality of leads for connecting to an integrated circuit and a resistor which is integral with the leadframe and connects selected conductive pads to form a resistive connection between two of the leads.

We claim: 
     
       1. An apparatus for sensing electrical parameters in an integrated circuit package comprising: a leadframe;   an interconnect pattern integral with the leadframe including a plurality of patterned conductive pads connected to a plurality of leads for coupling to an integrated circuit;   a resistor coupling with selected conductive pads forming a resistive coupling between two of the leads;   a measurement circuit coupled to the interconnect pattern leads to measure electrical parameters across the resistor: and   a temperature compensation circuit to compensate for variations in the sensed electrical parameters measured across the resistor resulting from temperature variations.   
     
     
       2. An apparatus as in claim 1, wherein the temperature compensation circuit further comprises: a comparator having an inverted input terminal coupled to a first side of the resistor and having a noninverted input terminal coupled to a second side of the resistor.   
     
     
       3. An apparatus for sensing electrical parameters in an integrated circuit package comprising; a lead frame;   an interconnect pattern integral with the lead frame including a plurality of patterned conductive pads connected to a plurality of leads for coupling to an integrated circuit;   a resistor coupling with selected conductive pads forming a resistive coupling between two of the leads;   a measurement circuit coupled to the interconnect pattern leads to measure electrical parameters across the resistor; and   a temperature compensation circuit to compensate for variations in the sensed electrical parameters measured across the resistor resulting from temperature variations, the temperature compensation circuit including: a comparator having an inverted input terminal coupled to a first side of the resistor and having a noninverted input terminal coupled to a second side of the resistor; and   a first level shifter operating at a first current density coupled between the comparator inverted input terminal and the first side of the resistor; and   a second level shifter operating at a second current density different from the first current density coupled between the comparator noninverted input terminal and the second side of the resistor.     
     
     
       4. An apparatus for sensing electrical parameters in an integrated circuit package comprising; a lead frame;   an interconnect pattern integral with the lead frame including a plurality of patterned conductive pads connected to a plurality of leads for coupling to an integrated circuit;   a resistor coupling with selected conductive pads forming a resistive coupling between two of the leads;   a measurement circuit coupled to the interconnect pattern leads to measure electrical parameters across the resistor; and   a temperature compensation circuit to compensate for variations in the sensed electrical parameters measured across the resistor resulting from temperature variations the temperature compensation circuit including: a first multiple-emitter transistor having a collector terminal coupled to a reference voltage source, a multiple emitter terminal with n emitter regions coupled to a current source and a base terminal coupled to a node on a negative pole side of the current sensing resistor;   a second multiple-emitter transistor having a collector terminal coupled to the reference voltage source, a multiple emitter terminal with m emitter regions coupled to the current source and a base terminal coupled to a node on a positive pole side of the current sensing resistor.     
     
     
       5. An apparatus as in claim 4, wherein the temperature compensation circuit is adjusted by selecting a current density ratio which determines a temperature coefficient. 
     
     
       6. An apparatus as in claim 4, wherein the temperature compensation circuit further comprises: a first level shifter operating at a first current density coupled to the base terminal of the first multiple-emitter transistor; and   a second level shifter operating at a second current density different from the first current density coupled to the base terminal of the second multiple-emitter transistor.   
     
     
       7. An apparatus as in claim 4 wherein the measurement circuit measures current flow in the resistor. 
     
     
       8. An apparatus as in claim 7 further comprising a control circuit coupled to the measurement circuit for comparing a current measurement to a preselected threshold current value and for selectively disconnecting power to the apparatus in accordance with the comparison result. 
     
     
       9. An apparatus as in claim 4 wherein the measurement circuit measures voltage across the resistor. 
     
     
       10. An apparatus as in claim 9 further comprising a control circuit coupled to the measurement circuit for comparing a voltage measurement to a preselected threshold voltage value and for selectively disconnecting power to the apparatus in accordance with the comparison result. 
     
     
       11. An electronic circuit component comprising: a leadframe having a generally planar top portion and having, integral therewith, a conductive interconnect pattern including a plurality of interconnect segments for coupling to leads of an integrated circuit; and   a resistor coupling selected interconnect segments forming a resistive coupling between two of the leads;   a semiconductor chip including: a measurement circuit coupled to the leadframe interconnect pattern for measuring electrical parameters across the resistor;   a temperature compensation circuit coupled to the measurement circuit for compensating for variations in the sensed electrical parameters measured across the resistor which result from temperature variations.     
     
     
       12. A component as in claim 11, wherein the temperature compensation circuit further comprises: a comparator having an inverted input terminal coupled to a first side of the resistor and having a noninverted input terminal coupled to a second side of the resistor.   
     
     
       13. An electronic circuit component comprising: a lead frame having a substantially planar top portion and having, integral therewith, a conductive interconnect pattern including a plurality of interconnect segments for coupling to leads of an integrated circuit:   a resistor coupling selected interconnect segments forming a resistive coupling between two of the leads; and   a semiconductor chip coupled to the lead frame interconnect pattern including: a measurement circuit for measuring electrical parameters across the resistor; and   a temperature compensation circuit for compensating for variations in the sensed electrical parameters measured across the resistor which result from temperature variations, the temperature compensation circuit further including: a comparator having an inverted input terminal coupled to a first side of the resistor and having a noninverted input terminal coupled to a second side of the resistor;   a first level shifter operating at a first current density coupled between the comparator inverted input terminal and the first side of the resistor; and   a second level shifter operating at a second current density different from the first current density coupled between the comparator noninverted input terminal and the second side of the resistor.       
     
     
       14. An electronic circuit component comprising: a lead frame having a substantially planar top portion and having, integral therewith, a conductive interconnect pattern including a plurality of interconnect segments for coupling to leads of an integrated circuit;   a resistor coupling selected interconnect segments forming a resistive coupling between two of the leads; and   a semiconductor chip coupled to the lead frame interconnect pattern including: a measurement circuit for measuring electrical parameters across the resistor: and   a temperature compensation circuit for compensating for variations in the sensed electrical parameters measured across the resistor which result from temperature variations, the temperature compensation circuit further including:   a first multiple-emitter transistor having a collector terminal coupled to a reference voltage source, a multiple emitter terminal with n emitter regions coupled to a current source and a base terminal coupled to a node on a negative pole side of the current sensing resistor;   a second multiple-emitter transistor having a collector terminal coupled to the reference voltage source, a multiple emitter terminal with m emitter regions coupled to the current source and a base terminal coupled to a node on a positive pole side of the current sensing resistor.     
     
     
       15. A component as in claim 14, wherein the temperature compensation circuit is adjusted by selecting a current density ratio which determines a temperature coefficient. 
     
     
       16. An apparatus as in claim 15, wherein the temperature compensation circuit further comprises: a first level shifter operating at a first current density coupled to the base terminal of the first multiple-emitter transistor; and   a second level shifter operating at a second current density different from the first current density coupled to the base terminal of the second multiple-emitter transistor.   
     
     
       17. A component as in claim 14 wherein the measurement circuit measures current flow in the resistor. 
     
     
       18. A component as in claim 14 further comprising a control circuit coupled to the measurement circuit for comparing a current measurement to a preselected threshold current value and for selectively disconnecting power to the apparatus in accordance with the comparison result. 
     
     
       19. A component as in claim 14 wherein the measurement circuit measures voltage across the resistor. 
     
     
       20. A component as in claim 19 further comprising a control circuit coupled to the measurement circuit for comparing a voltage measurement to a preselected threshold voltage value and for selectively disconnecting power to the apparatus in accordance with the comparison result. 
     
     
       21. An apparatus comprising: a battery pack for coupling a battery cell between a positive terminal and a negative terminal;   a battery protection integrated circuit coupled to the battery pack and having a connection to the positive terminal and the negative terminal; and   a lead frame coupled to the battery protection integrated circuit including: an interconnect pattern including a plurality of patterned conductive pads connected to a plurality of leads for coupling to an integrated circuit; and   a resistor coupling to selected conductive pads forming a resistive coupling between two of the leads.     
     
     
       22. An apparatus according to claim 21, wherein: the battery protection integrated circuit is a plastic encapsulated integrated circuit; and   the resistor is an integrated current-sensing resistor coupled between two leads of the plastic encapsulated integrated circuit.   
     
     
       23. An apparatus according to claim 22 wherein the integrated resistor has a resistance value which ranges from 1 to 25 milliohms and a current capacity which ranges from 1 to 40 amperes, 
     
     
       24. An apparatus according to claim 22 wherein the resistor is a patterned conductive pad which is coupled to selected conductive pads of the lead frame, 
     
     
       25. An apparatus according to claim 24 wherein the integrated resistor is a copper patterned conductive pad having a width of approximately 8 mm and a length of approximately 300 mm in a winding pattern. 
     
     
       26. An apparatus according to claim 21 wherein the resistor includes a plurality of conductive metal wire bonds each of which couples two selected conductive pads. 
     
     
       27. An apparatus according to claim 26 wherein the resistor includes five substantially parallel gold wire bonds each of which couples two selected conductive pads. 
     
     
       28. An apparatus according to claim 21 further comprising a measurement circuit coupled to the interconnect pattern leads to measure electrical parameters across the resistor. 
     
     
       29. An apparatus according to claim 28 further comprising a temperature compensation circuit to compensate for variations in the sensed electrical parameters measured across the resistor resulting from temperature variations. 
     
     
       30. An apparatus according to claim 29 wherein the temperature compensation circuit further comprises: a comparator having an inverted input terminal coupled to a first side of the resistor and having a noninverted input terminal coupled to a second side of the resistor;   a first level shifter operating at a first current density coupled between the comparator inverted input terminal and the first side of the resistor; and   a second level shifter operating at a second current density different from the first current density coupled between the comparator noninverted input terminal and the second side of the resistor.   
     
     
       31. An apparatus according to claim 29, wherein the temperature compensation circuit further comprises: a first multiple-emitter transistor having a collector terminal coupled to a reference voltage source, a multiple emitter terminal with n emitter regions coupled to a current source and a base terminal coupled to a node on a negative pole side of the current sensing resistor;   a second multiple-emitter transistor having a collector terminal coupled to the reference voltage source, a multiple emitter terminal with m emitter regions coupled to the current source and a base terminal coupled to a node on a positive pole side of the current sensing resistor.